One of the known sucker elements is arranged with its carrying body fixed firmly on the support tube. The sucker mechanism is located in the support body with a provision for vertical movement. The sucker does not provide for tensioning of soft bent paper sheets and in addition does not assure separation of bent paper sheets.
Another known sucker element is arranged on the support tube by means of an articulated joint which enables oblique adjustment of the sucker element in relation to the paper sheet. This sucker element has a disadvantage in that the articulated joint is complex and requires additional operator tension and detracts from operation of the feeder unit. To adjust the oblique position of the sucker element, the sucker element is removed, the articulated joint is replaced and the sucker element is remounted. The adjustment is a tedious job.